The United Federation of Teachers declared an impasse yesterday in its contract talks with the city and asked the state to intervene.

Under law, the state Public Employment Relations Board will now investigate and if it determines an impasse exists, will appoint a mediator.

The 80,000-member teachers union said its governing body voted to declare the impasse because there was no movement in the last two bargaining sessions on the key issues of retroactive salary hikes and using the expired contract as a base for the new one.

“This mayor doesn’t seem interested in working things out,” said UFT president Randi Weingarten. “For him, it’s my way or the highway.”

Mayor Bloomberg said he doesn’t think the talks are at an impasse.

The previous 30-month contract, which provided a 16 percent across-the-board wage increase, expired on May 31.

The current contract is 200 pages long.

The UFT says that on Feb. 6, the city proposed a bare-bones, eight-page contract imposing a 20 percent pay cut. The union rejected it.